Unable to create a RabbitMQ instance using RabbitMQ cluster Kubernetes operator - docker

Question

I'm trying to create a RabbitMQ instance using RabbitMQ cluster Kubernetes operator, but there is an issue with PersistentVolumeClaims. I'm running Kubernetes 1.18.8 using Docker Desktop for Windows.
I have installed the operator like this:
kubectl apply -f "https://github.com/rabbitmq/cluster-operator/releases/latest/download/cluster-operator.yml"
I have created this very simple configuration for the instance according to the documentation:
apiVersion: rabbitmq.com/v1beta1
kind: RabbitmqCluster
metadata:
name: nccrabbitmqcluster
It seems to create all of the objects it is supposed to create, but the pod gets stuck on pending state:
$ kubectl get all | grep rabbit
pod/nccrabbitmqcluster-server-0 0/1 Pending 0 14m
service/nccrabbitmqcluster ClusterIP 10.100.186.115 <none> 5672/TCP,15672/TCP 14m
service/nccrabbitmqcluster-nodes ClusterIP None <none> 4369/TCP,25672/TCP 14m
statefulset.apps/nccrabbitmqcluster-server 0/1 14m
There seems to be an unbound PVC according to the pod's events:
$ kubectl describe pod/nccrabbitmqcluster-server-0 | tail -n 5
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning FailedScheduling <unknown> default-scheduler running "VolumeBinding" filter plugin for pod "nccrabbitmqcluster-server-0": pod has unbound immediate PersistentVolumeClaims
Warning FailedScheduling <unknown> default-scheduler running "VolumeBinding" filter plugin for pod "nccrabbitmqcluster-server-0": pod has unbound immediate PersistentVolumeClaims
According to the events of the PVC, it is waiting for a volume to be created:
$ kubectl describe pvc persistence-nccrabbitmqcluster-server-0
Name: persistence-nccrabbitmqcluster-server-0
Namespace: default
StorageClass: hostpath
Status: Pending
Volume:
Labels: app.kubernetes.io/component=rabbitmq
app.kubernetes.io/name=nccrabbitmqcluster
app.kubernetes.io/part-of=rabbitmq
Annotations: volume.beta.kubernetes.io/storage-provisioner: docker.io/hostpath
Finalizers: [kubernetes.io/pvc-protection]
Capacity:
Access Modes:
VolumeMode: Filesystem
Mounted By: nccrabbitmqcluster-server-0
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ExternalProvisioning 27s (x23 over 19m) persistentvolume-controller waiting for a volume to be created, either by external provisioner "docker.io/hostpath" or manually created by system administrator
My understanding is that docker.io/hostpath is the correct provisioner:
$ kubectl get storageclasses
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
hostpath (default) docker.io/hostpath Delete Immediate false 20d
I can't see any PVs related to PCS:
$ kubectl get pv | grep rabbit
Why isn't the volume created automatically and what should I do?

Answer 1

Yes, your local hostpath can not work as dynamic volume provisioner. This operator needs an storageclassname which can dynamically create PVs.
In your case, your operator waiting continuously for PV to get created. In stead you can manually create an PV and PVC if you are doing in local machine.
Check this example - https://github.com/rabbitmq/cluster-operator/blob/main/docs/examples/multiple-disks/rabbitmq.yaml
If you are going to try any cloud provider like AWS then its pretty easy. Deploy EBS CSI driver in your cluster which will create an storageclass for you and that storageclass will provision dynamic volumes.